Device and method for measuring currents in a bearing

摘要

A measuring method and a device that permit a better evaluation of bearing currents are disclosed. The method uses non-contact measurement of a bearing voltage. A non-contact voltage measurement is performed by means of a series circuit of capacitors. The bearing voltage can be detected especially well in this manner even in the high frequency range.

主权项

1. A device for detecting a bearing voltage across a bearing supporting a shaft, wherein the shaft is connected to an electric motor and wherein a measuring gap is formed between a first element attached to the shaft and a second element being attached to or being part of the electric motor or a working machine driven by the shaft, the device comprising:
at least one board arranged in the measuring gap and having a first electrically conductive layer facing the first element, a second electrically conductive layer facing the second element, a central insulation layer disposed between the first layer and the second layer, and a measuring circuit connected between the first conductive layer and the second conductive layer measuring a voltage produced across a first capacitance formed between the first conductive layer and the second conductive layer, wherein the produced voltage is related to a bearing voltage.